Grinding machinery



Aug. 30, 1932. L.'F. NENNINGER GRINDING NAQHINERY Filed Feb. 17, 1926 3 Sheets-Sheet l gnuenrov ,LE Nenninger Aug. 30, 1932. 1.; F. NENNINGER enmnnie MACHINERY Filed F65. -17 1926 3 Sheets-Sheet 2 mi s wlu.

1932- Y L. F. NENNlNER 1,874,583

GRINDING MACHINERY Filed Feb. 17, 1926 s Sheets-Sheet 5 LE Nenn'mg'er Patented Aug. 30, 1932 UNITED? STATES PATENT OFFICE LESTER NENNINGER,.OI'. OINCINNATL OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, IO

OHIO

GRINDING. MACHINERY Application filediFebruary fl, 1926. Serial No. 88,961.

ment to these parts, which feeding-maybe varied to Withina thousandth of aninch and which may bedefinitely-limited to avoid undue removal of stock from the work.

One of the objects of the present invention-isthe provision of a novel and improved feed mechanism-facilitating the manual or automatic selective control of the feeding movement of the machine.

A further-object of the invention is the provision of a mechanism which' may be accurately set todefinitely limit'the feeding movement of the parts: irrespective or whether the automatic orthe manual feed is being utilized.

eration of the feed-controlli-ng device thru greater than 360 degrees without interference from the: normal :stop and =feed: device.

of the machine.

An additional object "of the invention is the provision ota :structurerfor control by either the reciprocationof the work-support or by a direct drive 'froma rotating portion of the machine in which the parts shall be so related as-to eliminate liability of breakage of the control devices even though bot'h sets 0t actuating mechanism therefor bessimuh taneously employed.

Further objects and advantages of the present invention should be readily apparent by reference to the following specifications taken in connection with the accompanying drawings and it will be understood: that any modifications in. the specific structural 'detailssshbwn and describedimay bemadewithin. the scope of the appended claims withoutdeparting from. or exceeding the spirit of the invention.

Figure lis a front elevation of a grinding machine with the improved control mechanism applied thereto.

Figure 2 is a vertical sectional view taken as on the line 2-2.ofFigure 1.

Figure 3' is a section on the line 33 of Figure 2.

l igure l'is a horizontal section taken on.

line of Figure 1.

Figure 5 is an enlarged fragmentary View of the pawl mechanism and ratchet wheel.

Figure 6 is a similar View showing the parts in a diii erent adjustment.

Figure 7 is asectional view on the line 77 of Figure 6.

Figure 8 is a vertical section on line 88 of Figure '7, looking in the direction indicated by the arrows.

Figure 9 is a fragmentary View showing thepawl in engaged position.

Figure 10 is a sectionon the line 10l0 of Figure 9.

Figure 11 is a section on the line 11l1 of :Figure 4, and

Figure -12.is a section on the line.1212 of Figure 6. i

In: theperformance of precision grinding operations such as the'formation oi axles or other cylindrical .work, the work is held between rotatable head and tail stocks and nor mally the supporting carriage for these are given. a back; and forth or reciprocating movement. This movement carries the work past the surface of a rotating grinding wheel. Asthe stock is removed from the workpiece it is necessary to either feed the carriage toward .thezstone or the stone toward the work as by a cross-screw mechanism. In some'instances it is desirable to use automatic means for producing this feed at or near the completion of each Work stroke or reciprocation of the table. In other instances the table may be stationary or for'other reasons it may be desired to have the feed constant or intermittent but not dependent upon the reciprocation-of the table. The present invention contemplates attaining all of these results thru the use of a ratchet member on the feed with the ratchet when at position of rest.

tive strokes of the pawl according to the de-" gree of feed desired and said means also serve to hold the pawl out of engagement This makes it possible to back off the feed manually without interference between the teeth of the ratchet and the pawl in counterdistinction to prior-art devices in which the pawl has remained in constant engagement with the ratchet teeth and thus prevented such manual reversing. 7 e

In addition to the foregoing the pawl mechanism inthe present invention is sovconstructed that it may be swung into an intermediate position to provide clearance for the stop mechanism on the ratchet wheel or may be moved into a reverse position and when in said latter reversed position it will disconnect the automatic pawl reciprocating mechanism both from thelever and the positively driven cam. In addition it will interlock with a bracket on the base holding the pawl rigid with the base and projecting into the path of movement of the stop on the ratchet wheel to definitely limit the positive manual actuation of the feed mechanism of which the ratchet forms a part.

In the specific machine chosen for illustration of the general principles of the present invention, the reference character A designates the base or bed of a machine provided with the carriage B having an in and out or feeding movement. Mounted on carriage B is the transversely shiftableslide C bearin headstock D and tailstock E for rotata ly supporting and driving the cylindrical workpiece F. Mounted upon base A in fixed bearings is spindle G of the grinding member II. It is to be understood that these parts are of general convert tional construction and while mention has been made of carriage B and associate parts being movable in and out for feeding toward and from the grindstone H, this feeding movement may be applied with equal facility to the grindstone, the controls ineither event being the same and there beingno change in the principles of the invention so far as herein claimed.

To cause the in and out or feeding movement of the table, use is made of feed screw 15 swiveled to carriage B and having engagement with fixed nut 16 on the base. Speed reduction gearing 17 operatively connects feed screw 15 with feed-controlling ratchet wheel 18 having the peripheral teeth 19. This ratchet wheel has a conventional micrometer adjustment mechanism 20 including the pull-pin handle 21 selectively engageable in the sockets 22 in the rim of the wheel. lVhen the handle is interlocked with the wheel, thewheel may be manually turned and serves thru gearing 17 to shift feed screw. 15.

In addition to this manual actuation of the feed wheel ratchet and thus the screw, mech anism is provided for a double automatic actuation thereof. This mechanism includes the oscillat'able pawl carrier arm 23 bearing pawl member 24: with tooth 25 for selective interlocking engagement with the teeth 19 of the ratchet. The pawl is secured on oneend of rock shaft 26 journaled in the outer end of pawlcarrier arm 23 while on the opposite: end of the shaft, as indicated in Figures7 and 10, is the bell-crank block 27 having pin bearing arm 28 and stop-engaging arm 29. As shown both the pawl'and the block are pinned to the, rockshaft to swing as a, unit relative to the carrier arm 23.- i

1 Considering firstthe intermittent feeding j action as imparted to the screw 15 at the ends of'the table stroke, the table is provided with the pair ofadjustable dogs 30 adapted to al ternately engage pin 31.011 rock level 32 supported by shaft 33. This shaft as shownin Figure 11 is also provided with wedge block 34 engagingtho inclinedor cam. face35 of rock lever 36 connectedv by drag-link 37 with pin 38 on rock arm 39. Pin 38 also serves as a pivot for link 40 whose other end is connected with'the pawl carrier arm 23. Movement to the left of the drag link 37 caused.byinter-engagement of surfaces 34 and 35 will, push-the arm and pawl to the left in Figure 1 and thus give a step advance .1 :-;3

to ratchet wheel 18. Thetable movement serves to impartl-his action to the part 3 while at thesame time rocking of lever32 serves thru the connection'shown at 41 and suitable conventional mechanism to reverse carrier and pawl'forward imparting a step by step rotation to ratchet wheel 18. As the result there is a step by'step feeding action of the carriage for each change in direction of movement or reversal of the-table, the feed being coupled with the automatic, reverse arm. 7

It will be understood this arm maybe thrown out of operation by withdrawal of pin 31 from the path of reverser. dogs 30. To' actuate drag link. 37 toward the right plunger is coupled by pin 45 actuating thru slot46 with the link 37 as is clearly illustrated in Figure 4.

Pivot pin 38 is supported by arm 39 secured on the end of the stub shaft 48 which has loosely mounted thereon block 49 having the cam follower 50. This follower engages the-eccentric roller or cam 51 on shaft 52 driven thru reduction gearing 53 from trans- 7 mission shaft 54 which is suitably coupled headstock and workpiece F witha suitable source of power such as the power rotating means for the headstock whereby. the cam shaft 52 rotates in pre-de termined timed relation to tne rotation of the actuated thereby.

. It will thus be seen that the rotation of the .cam provides a power-actuating mecha nism pushing and urging the member 49 about shaft 48 in the same direction that the is not reciprocated or where it is desired to have the feed at certain predetermined ratio to the speed of rotation'of the work, use is made of the clutch spool 55 keyed on shaft 48 and shiftable by push and pull pin 56.

This spool has a notch or other clutch portion as at 57 interlocking with clutch portion 58 on member 49 to secure the member for movement with the rockshaft. Movement of the cam will be intermittently transmitted thru the cam follower and its block and thru rockshaft 48, arm 39 and link 40 to the pawlcarrier for reciprocation thereof.

By reference to Figure 11 it will be noted that the pawl-actuating mechanisms just described provides what is known as an open system, that is to say both cam 51 and cam 34 urge the inter-connected parts toward the left, but have no positive action in the opposite direction so t-hatthe parts are free at all times to move in said opposite direction and away from either of the actuating members. This eliminates liability of cramping or breakage of the parts due to carelessness in operatively associating one actuating memher without disconnecting the other.

It will further be noted that the present system provides for a definite maximum throw of the pawl carrier and associate parts in one direction while leaving the movement in the opposite direction entirely to the influence of the spring 44. To vary this resiliently. urging return movement and thus to control the number of teeth 19 skipped by the pawl in its return movement, use is made of bracket 157 on the frame-plate 43 and a stop-screw 158. This stop screw is so positionedthat it partially engages pawl car-i rier arm 23 on the reverse movement of the latter and partially engages depending arm 29 of block 27. As a result the pawl carrier slides backward with the pawl dragging over and in engagement with the ratchet teeth until arm 29 touches the stop-screw when the action will be to swing the pawl upward against the action of gravity, lifting it out of engagement with the ratchet teeth as shown in Figure 8. This permits of manual adjustment of the ratchet wheel in a reverse or outward feeding direction without attention to the pawl. On the other hand as soon as the pawl carrier arm is actuated in a feeding direction, arm 29 will move away from screw 158 as shown in Figure 9 when the gravity action both of the pawl and of arm 28 on L-shaped block 27' will force the pawl into proper inter-locking engagement with the ratchet teeth. In addition the position of the pawl is such that pressure applied to link 40 will clamp the pawl more firmly in engagement with the ratchet tooth and eliminate liability of swinging by or slippage'of the parts under strain.

When it is desired to manually actuate the ratchet wheel for in or out feeding movements of the work-carriage, the pawl is swung upward to an intermediate position as indicated in Figure 6 and retained by spring latch or detent 59 shown in Figure 7. In this position the pawl carrier arm is free to swing backward and forward, but the pawl itself is retained in sufficient height to entirely clear adjustable stop-block 60. This block itwill be noted is slidably retained as by groove 61 of the ratchet wheel and is provided with a stop-shoulder 62 for purpose hereinafter described and in addition has a shield portion 63 on which the pawl tooth 25 will idly ride when the ratchet wheel has been manually or automatically advanced to pre-determined stopping position in a manner well known in the art. This stop block it will be understood is adjustably held by latchpin 64 interlocked with a selected tooth or teeth 19.

The necessity for securing the pawl in an intermittent inoperative position resides in the fact that in some instances more than a complete revolution must be given to the ratchetwheel for initial relative positioning of the work and the grinding wheel, and the pawl must in some way be gotten out of the road of the stop block. This is readily accomplished and an entirely free adjustment of the parts made possible by the structure here illustrated.

In addition the pawl and stop block have a very desirable co-operative relation in connection with manually controlled feed. This relationship is illustrated in Figure 5. The

pawl is shown as reversely shifted to a position where pin 65 on arm 28 interlocks with slot 66 of bracket 157. The position of this slot is such that the pawl carrier arm must be moved forward for such engagement, a dis- Q tance sufiicien-t to shift cam follower and ii of the stop block as the ratchet wheel is manna-ll rotated in a counter-clockwise feeding stro e. Manual feeding is consequently definitely limited at a pre-determined point by this adjustment of the parts.

' v To facilitate the manual reverse rotation of the ratchet wheel more than a complete turn, the stop block is provided with the inclined rear projection 68 which on reverse rotation will cam the pawl upward from stopping position to a semi-raised neutral position where positive actuation of the pawl arm will still be prevented butthe pawl is out of the path of movement of the stop block.

a From the foregoing it will be seen that there has been provided a novel combined cross-feed control mechanism for a grinding machine embodying a simple pawl structure in combination with actuating means therefor, whereby the pawl may operate the crossfeed from the table lever or the headstock drive selectively as desired when in one position,also that a stop member is provided in connection with the pawl-engageable feed ratchet, which stop member will co-operate with the pawl in one relationship to check the automatic actuation of the cross feed and in addition will co-operate with the pawl in another relation to check and limit the manual cross-feed operation of the machine.

I claim. a Y

1. A grinding machine including a bed, a work-support and a grinding member car ried by the bed, means for imparting a relative feeding movement to said parts on the bed, saidfeeding mechanism including a ratchet wheel, a pawl shiftable t0 diflerent effective positions for co-operation with the ratchet when in one position and with a stop member when in reversed position, and a stop member on the ratchet wheel selectively engageable with the pawl, when the pawl is in one position to limit the operation of the pawl and engageable with the pawl when the pawl is in its other or reversed position to positively limit movement of the ratchet wheel.

2.'A grinding machine including a bed, a grinding wheel and a work support carried by the bed, means for relatively shifting said parts onlthe bed including a ratchet member and an actuating pawl therefor, means for reciprocating the pawl, additional disengage,

with feed mechanism of a feed limiting mem\ ber carried thereby, and a pawl shiftable into different efi'ective positions and operatively engageable with the feed mechanism when in one position to actuate said feed mechanism and engageable with the limiting device when in a reverse position to limit actuation of said mechanism.

4. A grinding machine including worksupporting and work-grinding means, feed mechanism for relatively shifting the parts including a ratchet and an actuating pawl therefor, a cam means intermediate thecam and pawl for imparting motion to the pawl, and means for locking the pawl in position to render said intermediate means inoperative without disturbing normaloperative adjustment of the actuating mechanism therefor.

5. In a grinding machine, the combination with the grinding element and the work-support, of means for imparting a relative feed ing movement to said parts, said means including a feed screw and a ratchet wheel coupled with the screw, a pawl carrier pivoted concentric with the ratchet wheel and projecting radially therebeyond, a gravity pawl pivotally secured to the projecting portion of the carrier and shiftable into different operative positions, a stationary bracket member carried by the machine and disposed adjacent the ratchet wheel andin the path of movement of the carrier, means on the bracket arm adapted to engage the carrier and pawl to limit the movement of said two parts in one direction when the pawl is in one position, and additional interlocking means on the pawl and bracket adapted to secure the pawl out of engagement with the ratchet and against movement in any direction when the pawl is in a difierent operative position.

6. A machine of the character described, including a grinding element and a work holder, means for relatively feeding said parts including a pawl'and ratchet mechanism, means for positively urging the pawl in a direction to actuate the ratchet, resilient means for urging the pawl in the opposite direction, and means engageable with the pawl for securing the pawl out of engagement with the ratchet and in position to prevent its operation by the actuating means therefor.

7 Feed control mechanism for a cylindrical grinder, including a feed ratchet, a pawl carrier pivotally associated with said ratchet, link mechanism coupled with said carrier, resilient means for actuating the link mechanism in one direction, an intermediately pivoted rock lever associated with one end of the link and having at its opposite end a cam portion for actuation thereof operable positively only in the direction opposite to that in which it is operated by the resilient means, a second rock arm operativelv associated with the opposite end of the link, a cam driven block adjacent said rock-arm operable positively only in the direction opposite to that in which it is operated by the resilient means, and means controlled by a device whose position is unaffected by change of position in operation of any of the preceding elements for operatively connecting the block with the rock-arm for supplemental actuation of the link mechanism when desired.

8. In mechanism of the character described, the combination with feed mechanism including a ratchet-toothed wheel, of a pawl carrier pivoted concentric with the wheel, a rock shaft journaled in the pawl-carrier and bearing a pawl, a control member for the pawl carried by the rock shaft, said pawl and control member having their major portions disposed to the same side of the rock-shaft, whereby their weight will actuate the pawl toward the ratchet, a bracket on the machine adjacent the pawl-carrier having a portion disposed in the path of movement of the control member, and interlocking means on the control member and bracket for positively locking the pawl and carrier against pivotal movement.

9. In a mechanism of the character described, the combination with the cross feed mechanism, of a ratchet wheel coupled therewith, a pawl carrier pivoted concentric with said wheel, a rock-shaft journaled in said carrier exterior to the ratchet portion of the wheel and bearing a gravity pawl, a plate secured on the rock-shaft and having a portion projecting rearwardly of the carrier when the pawl is in engagement with the ratchet, means for oscillating the carrier to cause the pawl to advance the ratchet with a step by step movement, a bracket on the machine having a portion projecting in the path of the oscillating carrier, and an adjustable stop member on the bracket having a portion for engagement with the projection on the plate and a portion for engagement with the carrier, whereby on reverse movement the stop member will engage the plate to raise the pawl and subsequently engage the carrier to limit the movement of the parts in that direction.

10. In a grinding machine, the combination with the cross-feed mechanism, of a ratchet wheel coupled therewith, a pawl carrier mounted concentric with the wheel for oscillation relative thereto, a pawl on the carrier for operative engagement with the ratchet in one direction of oscillation of its carrier, a weighted member coupled with the pawl for actuating the latter into engagement with the ratchet, a bracket on the machine adjacent said member, said bracket having a retaining slot formed therein, a locking pin carried by the member for engagement with the slot when the pawl is in raised position to secure the pawl and carrier against oscillatory movement, the length of the slot being suflicient to'permit of reverse swinging of the pawl substantially into engagement with the wheel, and a stop member adjustably mounted on the ratchet wheel for engagement with the pawl in reversed position to limit the manual actuation of the ratchet wheel.

11. Size-controlling mechanism for ap plication to grinding machines including a cross-feed screw and a manually actuable operating wheel therefor having a peripheral ratchet portion, a pawl member supported for oscillation adjacent the ratchet and shiftable to and from ratchet engaging position, a stopblock slidably mounted on the wheel and retained in adjusted position by engagement with the ratchet portion thereof, a bracket carried by the machine adjacent the ratchet and having an elongated slot therein, a member coupled with the pawl movable when the pawl is disengaged from the ratchet for cooperation with the stop block, said member having a pin slidably engaged in the slot whereby the pawl associated therewith may be depressed into the path of movement of the stop block or may be raised to allow the block to pass freely thereunder without disengagement of the pin and slot, the stop member having a cam portion at one side thereof adapted to engage and raise the pawl out of the path of block on reverse rotation of the wheel, whereby dis-engaging manual feed is facilitated.

12. Cross feed mechanism for a grinding machine including a ratchet wheel and a cooperating pawl, a stop block on the wheel, disengageable means for oscillating the pawl to actuate the ratchet wheel, and additional means for alternatively rigidly securing the pawl against oscillatory movement and in the path of movement of the block whereby a stop for manual oscillation of the ratchet wheel is provided.

13. A grinding machine including worksupporting and work-grinding means, feed mechanism for effecting a shifting of the parts one with respect to the other including a ratchet and an actuating pawl therefor, a driven cam member, means for normally operatively connecting the cam and pawl for actuation of the latter including a follower engageable bv the cam member, and means for securing the connect ons including the fol lower, in retracted position whereby the follower will be held out of the operative path of the cam member, said means comprising interengageable parts on the pawl member and the body of the machine for positively securing the pawl in a fi ed in operative position.

LESTER F. NENNINGER. 

